The present invention relates to housings for electrical assemblies and more particularly to a method of assembling an electrical apparatus in a housing and the system it produces. Assembly of electrical apparatus must be performed with great care given the sensitive components and connections involved. The housings on the other hand must be robust in order to offer its components protection from physical as well as environmental effects. Accordingly, housings comprise robust materials, such as metals. The metal must be handled with care around the electrical apparatus and associated components so as not to damage the latter with the former. The housing may further share surfaces with components to be accommodated therein. Accordingly, a housing top may also comprise the printed circuit board which facilitates operation of the electrical apparatus accompanied within the housing. The present invention will be discussed, by way of example, as a housing of the latter type or cap. Herein, the cap will be discussed with respect to a display device to be housed substantially therein. However, the present invention is not limited to caps and display devices and may find other application and utility as envisioned by one skilled in the art.
Caps are known to comprise a frame in which sits components whose protection from external sources is sought. Accordingly, caps tend to be made of rigid material formed into a functionally useful shape—such as a rectangular housing. The housing generally comprises a base with a portion removed leaving a border to define a display area. Behind the display area in the direction of the housing generally sits the display portion of the electrical apparatus which the cap will house. Such display portions may include a liquid crystal display (LCD) screen optionally with a diffuser and/or prism arranged as known in the art. Accordingly, the LCD screen is visible from outside the cap.
The cap includes at least a pair of side walls spanning from the base to a top portion. The side walls may include openings through which connections to apparatus accommodated within the cap may be facilitated. The cap may not necessarily include a top. Rather with some constructions, the printed circuit board, required for operation of the apparatus accommodated within the cap may substitute or function as the top. This has the obvious advantage of requiring fewer parts making for an easier and lighter assembly as well as access to the board. However, this advantage has the problem that during assembly, an appropriate spacing between board and components of the apparatus accommodated within the cap must be maintained. In particular, the board must be properly supported so as to offer the relatively same protection to the components and apparatus accommodated within the cap as the cap side walls and base.
A solution to the aforementioned problem includes affixing spacing legs onto the board during assembly. The legs are made of a sufficiently rigid material so as to provide sufficient support and/or the transfer of supported force from a rigid supporting surface. The legs have a select length that corresponds to a length of the cap side walls. The legs length positions the cap at a select distance above the base, the distance being sufficient to suitably accommodate the electrical apparatus and components thereof between base and board. The legs are typically bolted or screwed onto the board. Afterwards, electrical connections are effected between board and components of the apparatus. This is typically performed by use of ribbon cables and the like. Then the components and board with legs are inserted into the cap or the cap is placed over the components and board and the board is secured into place.
The above solution includes problems stemming from use of the legs. The legs are of a sufficiently rigid material so as to impart support from the base to the board. The rigid legs however, also tend to cause damage to the components and electrical apparatus when the legs come into contact. Given the limited space within a cap, the assembly tolerances are such that contact is inevitable absent particular caution and care. Damage from the contact is not limited to component or apparatus, but may also include damage to connections, especially ribbon connections. Accordingly, a need exists for an assembly which when assembled does not cause the aforementioned damage to components, apparatus nor connections. In addition, an on-going need exists in balancing the need to maximize the space within the cap while at the same time maximizing available assembly tolerances.